Cutoff machine



CUTOFF MACHINE Q J1me 1957 J. A. LANGE 3,325,946

Filed Oct. 22, 1964 2 Sheets-Sheet 1 *42 f4 gg g5 z INVENTOR J'OS'P/l A. LANGE ATTORNEYS J. A. LANGE CUTOFF MACHINE June 20, 1967 2 Sheets-Sheet 2 Filed Oct. 22, 1964 INVENTOR JOSEPH A. AAA/6f WA O -ZM ATTORNEYS United States Patent 3,325,946 CUTOFF MACHINE Joseph A. Lange, Passaic, N.J., assignor to Raybestos- Manhattan, Inc, Passaic, N.J., a corporation of New Jersey Filed Oct. 22, 1964, Ser. No. 405,787 6 Claims. (Cl. 51-33) This invention relates to cutoff machines, and more particularly to such machines using an abrasive cutting wheel.

Cutoff machines using a thin abrasive disc of large diameter are already known. The disc is driven at high speed and is movable toward or away from the work, as by mounting the same rotatably at the free end of a pivoted arm. The arm may be provided with appropriate means, such as a counterweight or a spring to normally raise the wheel from the work, and the arm may be provided with a handle which is used to move the wheel against the work.

It is already known that the cutting action is speeded, and the power requirement reduced, by reciprocating the wheel in a direction transverse to the direction of the feed movement of the Wheel. (Usually the wheel is fed downward and is reciprocated horizontally.) Heretofore a relatively long slow stroke has been employed, for example, a reciprocation of say two inches, at a rate of say forty-five per minute.

The object of the present invention is to generally improve cutoff machines of the specified character. More specific objects are to speed the cutting operation; to simplify the main dn've mechanism; and to reduce vibration. I have discovered that these objects may be fulfilled by utilizing a rapid reciprocation and a short stroke. For example, in a cutoff machine using a cutting wheel of say sixteen to twenty inches in diameter, and cutting round steel bar having a diameter of say tow to four inches, the reciprocation preferably is approximately one-eighth inch at a rate of about two hundred and forty reciprocations per minute.

Another object of the invention is to provide an improved toggle linkage for reciprocating the cutting wheel. I

To accomplish the foregoing general objects, and other more specific objects which will hereinafter appear, my invention resides in the cutoff machine elements and their relation one to another, as are hereinafter more particularly described in the following specification. The specification is accompanied by drawings, in which:

FIG. 1 illustrates somewhat schematically a cutoff machine embodying features of my invention, the wheel being shown in raised position;

FIG. 2 is a fragmentary end elevation with the wheel in down position;

FIG. 3 is an elevation corresponding to a part of FIG. 1, but with the cutting wheel in down position; and

FIG. 4 is a section taken approximately in the plane of the stepped line 4-4 of FIG. 3.

Referring to the drawing, and more particularly to FIG. 1, the cutoff machine comprises an abrasive cutoff wheel 12, a motor 14, and drive means, in this case the belts 16 and 20, to rotate the wheel 12 at high speed. There is a pivoted arm 22 carrying the wheel 12 for feed movement toward or away from the work. A lever 24 carries the pivoted end of the arm 22, as shown at 26, to reciprocate the arm 22 and the wheel 12 in a direction transverse to the direction of feed. In the usual case and as here illustrated, the direction of feed is downward, and the reciprocation is horizontal. There is additional motordriven linkage 28, 30, and 32 to reciprocate the lever 24 and arm 22, and the linkage and its drive are so designed as to provide a rapid reciprocation of short stroke, the stroke being in a range of from one-sixteenth 3,325,946 Patented June 20, 1967 inch to three-eights of an inch, and at a rate of from one hundred twenty to three hundred sixty reciprocations per minute. In preferred form, the stroke is one-eighth inch at a rate of two hundred forty per minute.

In FIG. 1 it will be seen that a counterweight 34 and cable 35 normally move the arm 22 and wheel 12 upward from the work or stock 36 which is to be cut. A handle 38 is mounted on arm 22 for moving the arm and wheel downward for the cutting feed movement.

Referring now to FIG. 3, lever 25 is pivoted at 40 on a fixed bearing 42 mounted on or cast integrally with the machine table or frame 44. The parts 28 and 30 form a toggle linkage which is connected at one end to the upright lever 24, as shown at 46. The toggle linkage is connected at its other end to a fixed bearing 48, as shown at St). Bearing 48 is secured to or formed integrally with table 44. The connecting rod 32 is connected at its upper end to the common or middle pivot 52 of the toggle linkage, and is connected at its lower end to a crank disc 54 having a crank pin 56. The crank is driven by a gear reduction motor 60. It will be seen that as the crank rotates it moves the toggle linkage above dead center as shown in broken lines at 28 when the crank is at the top of its stroke. The toggle linkage is moved downward below dead center when the crank is at the bottom of its stroke. This causes a sideward oscillation at pivot 46 and a consequent horizontal reciprocation of the arm 22 and cutting wheel 12. The toggle linkage causes two reciprocations (four excursions) for each rotation of the crank.

Reverting to FIG. 1, the main drive motor 14 carries a pulley 62 driving belt 16 which drives a pulley 64. The latter is either secured to or is formed integrally with a companion pulley which drives belt 20, and the latter extends along the arm 22 and is oscillatable and reciprocable with the arm. The belt 20 drives a pulley 66 which drives the cutting wheel 12. Because pulley 64 has the same axis as the pivot for arm 22 (the shaft 26), the drive of the cutting wheel 12 is unaffected by oscillation of arm 22 when moved toward or away from the work 36. The drive of belt 20 also is unaffected by horizontal reciprocation of the arm 22, because the belt and its pulleys simply move with the arm. The drive of belt 16 "ice is not significantly affected by the horizontal reciprocation of the arm 22 because the belt is long relative to the horizontal stroke which is very short, say one-eighth inch. This constitutes an incidental extra advantage of the short stroke here employed. Moreover, the reciprocation of pulley 64 is tangential and does not noticeably change the distance between pulleys 62 and 64.

, Referring to FIG. 4, the arm 22 may have a H section, as indicated. This lightens the arm without loss of rigidity. At the ends of the arm the web is enlarged to form sturdy full-length bearings. Referring to FIG. 2, the end bearing 70 carries a short shaft 72. The hub 74 of cutting wheel 12 is mounted at one end of shaft 72, and a pulley (not shown) i mounted at the other end. The pulleys preferably have multiple V grooves, and the belts are preferably multiple V belts.

Referring again to FIG. 4, the bearing at the other end of arm 22 is received between the upper end 82 of the upright lever 24, and the upper end of a companion arm 84 which resembles the upper end of lever 24. The parts 82 and 84 are secured to a common pin or pivot 40 so that they oscillate in unison. Pin 40 is carried in the fixed bearing 42 previously referred to.

Shaft 26 is carried at the upper ends of the parts 82 and 84, and it also carries the bearing 80 of arm 22. Shaft 26 further carries the two pulley (not shown in FIG. 4) needed for the main belt drive of the cutting wheel. These pulleys are mounted immediately adjacent 3 one another on one end of shaft 26, and the upright and horizontal belts 16 and 20 (FIG. 3) are adjacent one another. The pulleys may rotate freely on the shaft 26, or may be secured to the shaft.

Referring to FIG. 4, there are two collateral toggle links 30 which straddle the lower end of lever 24. Referring next to FIG. 3, the toggle link 28 is a single link having the same thickness as lever 24, so that the two collateral links 30 straddle the end of link 28. The other end of link 28 is pivoted on a fixed bearing 48 which is disposed alongside the link, as shown in FIG. 2. FIG. 2 also shows how the upper end of the connecting rod 32 is bifurcated at 90 to straddle all three links, of which the spaced links 30 are visible in FIG. 2, while the single link therebetween is concealed by the lever 24.

The table 44 is provided with a means or rest to hold the work begin cut. The work typically is round bar stock as shown at 36, and the rest or support then is preferably V-shaped, as shown at 100. The support 100 is cut away to clear the cutting wheel, as shown at 102 in FIG. 2.

Ina typical case, the abrasive wheel 12 may be from sixteen to twenty inches in diameter, and one-eighth inch thick. It may be made of silicon carbide, or aluminum oxide, or other such abrasive, depending on the material to be cut. The main drive motor 14 may be a seven and one-half horsepower motor for a sixteen-inch wheel, or a ten horsepower motor for a twenty-inch wheel. The motor drives the cutting wheel at a peripheral speed of, say, ten to fifteen thousand feet per minute.

The auxiliary motor 60 is preferably a small, say onequarter horsepower, gear reduction motor for slow-speed output. It preferably drives the crank at one hundred twenty r.p.m., which because of the toggle linkage, causes reciprocation of the cutting wheel at two hundred forty per minute. If the motor speed is adjustable, it preferably provides a range of from sixty to one hundred eighty rpm. for the crank disc, with a corresponding range of one hundred twenty to three hundred sixty reciprocations per minute. The horizontal stroke caused by the illustrated linkage may range from one sixteenth inch to three eighths inch, or better from three sixteenths inch to five sixteenths inch, and most preferably is one eighth inch.

Working on machine steel bar having a diameter of three and one-half inches, and using a sixteen inch cutting wheel of Grade 430 made by Raybestos-Manhattan, Inc., of Passaic, N.I., the bar was cut in forty-eight seconds when using a stroke of three thirty-second inch at a rate of two-hundred-forty per minute. When the stroke was increased to five-sixteenths inch, the rate of reciprocation was reduced to one hundred twenty per minute to avoid excessive vibration. The longer stroke and slower reciprocation increased the cutting time for the same material to seventy-eight seconds. The wheel was a rubber bonded wheel, used for a wet cut, and the liquid used was water.

As another example, machine steel having a diameter of four one-eighth inches was cut with a dry cut, using a Raybestos-Manhattan, Inc. resin-bonded sixteen inch wheel of Grade 225. The cutting time with a stroke of fivesixteenths inch, at one hundred twenty reciprocations per minute, was sixty-seven seconds. By reducing the stroke to one-eighth inch and increasing the rate to two hundred forty per minute, the cutting time was reduced to forty-six seconds. A higher speed of, say three hundred sixty reciprocations per minute caused vibration and did not reduce the cutting time. The speed of two hundred forty per minute was not desirable with the five-sixteenth inch stroke because it caused vibration.

The two hundred forty and even a three hundred sixty rate was used with a shorter stroke than one-eighth inch, but the cutting time increased slightly (two to four seconds longer).

However, it is believed that in all cases the cutting time was reduced and the operation improved compared to the more conventional practice of using, say, a two-inch recip- 4 rocation at a rate of forty-five per minute. With no reciprocation at all the power requirements is so great that the motor is stalled.

-It is believed that the construction and operation of my improved cutoff machine, as well as the advantages thereof, will be apparent from the foregoing detailed description. Although quantitative values have been given in the foregoing description, such as the wheel diameter and wheel speed, etc., it will be understood that many of these values have been given solely by way of exemplification and are not intended to be in limitation of the invention. It will also be understood that while I have shown and described the invention in a specific form, changes may be made without departing from the scope of the invention, as sought to be defined in the following claims.

I claim:

1. A cutoff machine for cutting a work piece, said machine comprising an abrasive cutoff wheel, a pivoted arm carrying the wheel for feed movement toward or away from the work piece which is to be cut, a generally upright lever carrying the pivot of the arm, toggle linkage having a common or middle pivot and connected at one end to the lever and connected at the other end to a fixed bearing, a crank and connecting rod connected to the common or middle pivot of the toggle linkage, motor means for driving the crank and for driving the wheel, and means including a belt extending along and oscillatable with the arm for connecting the motor means to the cutoff wheel.

2. A cutoff machine for cutting a work piece, said ma chine comprising an abrasive cutoff wheel, a pivoted arm carrying the wheel for feed movement toward or away from the work piece which is to be cut, a generally upright lever carrying the pivot of the arm, toggle linkage having a common or middle pivot and connected at one end to the lever and connected at the other end to a fixed bearing, a crank and connecting rod connected to the common or middle pivot of the toggle linkage, a reduction gear motor for driving the crank, 21 main motor for driving the wheel, means including a belt extending along and oscillatable with the arm for connecting the main motor to the wheel, means to raise the, arm to lift the wheel from the work, and a handle on the arm for urging the wheel downward against the work.

3. A cutoff machine for cutting a work piece, said machine comprising an abrasive cutoff wheel, a pivoted arm carrying the wheel for feed movement toward or away from the work piece which is to be cut, a generally upright lever carrying the pivot of the arm, toggle linkage having a common or middle pivot and connected at one end to the lever and connected at the other end to a fixed bearing, a crank and connecting rod connected to the common or middle pivot of the toggle linkage, a reduction gear motor for driving the crank, a main motor for driving the wheel, and means including a belt extending along and oscillatable with the arm for connecting the main motor to the wheel, the linkage and reduction gear motor being so dimensioned and designed as to provide a rapid reciprocation of short stroke.

4. A cutoff machine for cutting a work piece, said machine comprising an abrasive cutoff wheel, a pivoted arm carrying the wheel for feed movement toward or away from the work piece which is to be cut, a generally upright lever carrying the pivot of the arm, toggle linkage having a common or middle pivot and connected at one end to the lever and connected at the other end to a fixed bearing, a crank and connecting rod connected to the common or middle pivot of the toggle linkage, a reduction gear motor for driving the crank, a main motorfor driving the wheel, and means including a belt extending along and oscillatable with the arm for connecting the main motor to the wheel, the linkage and reduction gear motor being so dimensioned and designed as to provide a rapid reciprocation of short stroke, the stroke being in a range of from one-sixteenth inch to three-eighth inch at a rate of from one hundred twenty to three hundred sixty reciprocations per minute.

5. A cut-off machine for cutting a work piece, said machine comprising an abrasive cutofi wheel, a pivoted arm carrying the wheel for feed movement toward or away from the work piece which is to be cut, a generally upright lever carrying the pivot of the arm, toggle linkage having a common or middle pivot and connected at one end to the lever and connected at the other end to a fixed hearing, a crank and connecting rod connected to the common or middle pivot of the toggle linkage, a reduction gear motor for driving the crank, 21 main motor for driving the wheel, and means including a belt extending along and oscillatable with the arm for connecting the main motor to the wheel, the linkage and reduction gear motor being so dimensioned and designed as to provide a rapid reciprocation of short stroke, the stroke being approximately one-eighth inch long at a rate of approximately two hundred forty reciprocations per minute.

6. A cutoff machine for cutting a work piece, said machine comprising an abrasive cutoff wheel, a pivoted arm carrying the wheel for feed movement toward or away from the work piece which is to be cut, a generally upright lever carrying the pivot of the arm, toggle linkage having a common or middle pivot and connected at one end to the lever and connected at the other end to a fixed hearing, a crank and connecting rod connected to the common or middle pivot of the toggle linkage, a reduction gear motor for driving the crank, a main motor for driving the wheel, means including a belt extending along and oscillatable with the arm for connecting the main motor to the wheel, means to raise the arm to left the wheel from the work, and a handle on the arm for urging the wheel downward against the work, the linkage and reduction gear motor being so dimensioned and designed as to provide a rapid reciprocation of short stroke, the stroke being approximately one-eigth inch long at a rate of approximately two hundred forty reciprocations per minute.

References Cited UNITED STATES PATENTS 411,839 10/1889 Taft 51-38 1,969,238 8/1934 Robinson 5198 2,855,733 10/ 1958 Allison 5l*3 3 X 3,046,707 7/ 1962 Obear 12513 X LESTER M. SWINGLE, Primary Examiner. 

1. A CUTOFF MACHINE FOR CUTTING A WORK PIECE, SAID MACHINE COMPRISING AN ABRASIVE CUTOFF WHEEL, A PIVOTED ARM CARRYING THE WHEEL FOR FEED MOVEMENT TOWARD OR AWAY FROM THE WORK PIECE WHICH IS TO BE CUT, A GENERALLY UPRIGHT LEVER CARRYING THE PIVOT OF THE ARM, TOGGLE LINKAGE HAVING A COMMON OR MIDDLE PIVOT AND CONNECTED AT ONE END TO THE LEVER AND CONNECTED AT THE OTHER END TO A FIXED BEARING, A CRANK AND CONNECTING ROD CONNECTED TO THE COMMON OR MIDDLE PIVOT OF THE TOGGLE LINKAGE, MOTOR MEANS FOR DRIVING THE CRANK AND FOR DRIVING THE WHEEL, 